This invention relates to an imaging system having a vacuum roller for transporting a recording medium.
Existing captstan imaging systems transport recording media by pulling the media through an imaging plane. Specifically, rollers in these imaging systems pinch the leading edge of the recording media and rotate to pull the media through the imaging plane. Because the leading edge of the recording media is pinched, images cannot be formed at, or near, the edge of the media.
In general, in one aspect, the invention is directed to a vacuum roller that features a roller having transverse holes and surface holes. Each of the surface holes intersects with at least one of the transverse holes. A cap mates to a portion of the roller where the transverse holes are exposed. The cap has a cavity that aligns to at least one of the transverse holes and remains substantially stationary during rotation of the roller. A vacuum device evacuates the cavity. This aspect of the invention may also include one or more of the following.
The vacuum device produces sufficient vacuum to substantially evacuate the cavity, produces suction in the at least one transverse hole, and produces suction in surface holes that intersect the at least one transverse hole. The cap mates to a side of the roller where the transverse holes are exposed. A second cap mates to another side of the roller where the transverse holes are exposed. The second cap has a second cavity that aligns to at least one of the transverse holes and that remains substantially stationary during rotation of the roller. The second cavity of the second cap is substantially aligned to the cavity of the cap.
The roller includes surface grooves that intersect the surface holes, and is made of plural segments. The surface holes are arranged in rows at substantially equal distances from one another. The cap forms a substantially air-tight seal with the roller. One or more valves control suction from the vacuum device to selectively evacuate the cavity.
In general, in another aspect, the invention is directed to an imaging system. The imaging system features a guide that transports a recording medium, and a roller that holds the recording medium in place to transport the recording medium through an imaging plane defined by a surface of the roller. A device forms an image onto the recording medium at the imaging plane. In this aspect of the invention, the roller includes a vacuum roller having transverse holes and surface holes. Each of the surface holes intersects with at least one of the transverse holes. A cap mates to a portion of the vacuum roller where the transverse holes are exposed. The cap has a cavity that corresponds to the imaging plane, aligns to at least one of the transverse holes, and remains substantially stationary during rotation of the vacuum roller. A vacuum device evacuates the cavity.
In general, in another aspect, the invention is directed to a vacuum roller that features a stationary inner roller having a cavity, and an outer roller that rotates about the stationary inner roller. The outer roller has holes that are adjacent to the cavity in the stationary inner roller. A vacuum device evacuates the cavity. This aspect of the invention may include one or more of the following features.
The stationary inner roller includes a second cavity. The vacuum device produces sufficient vacuum to substantially evacuate the cavity and to produce suction at the holes. The outer roller includes surface grooves that intersect the holes. The holes are arranged in rows at substantially equal distances from one another. The stationary inner roller and the outer roller are substantially concentric.
In general, in another aspect, the invention is directed to an imaging system, which includes a guide that transports a recording medium and a roller that holds the recording medium in place to transport the recording medium through an imaging plane defined by a surface of the roller. A device forms an image onto the recording medium at the imaging plane. In this aspect of the invention, the roller includes a stationary inner roller having a cavity, and an outer roller. The outer roller rotates about the stationary inner roller and has holes that are adjacent to the cavity in the stationary inner roller. A vacuum device evacuates the cavity.
In general, in another aspect, the invention features a vacuum transporting device. The device includes a belt having perforations therethrough that moves through an imaging plane, a chamber containing a cavity that is located adjacent to the belt, and a vacuum device that evacuates the cavity. The chamber may include holes that are located adjacent to the belt for suctioning air through the perforations.
Other features and advantages of the invention will become apparent from the following description, including the claims and drawings.